powerpc/4xx: Fix resource issue in warp-nand.c

The "ndfc-chip" device doesn't need any resources. All resources
are handled by the "ndfc-nand" device. Registering the same memory
resource twice causes "cat /proc/iomem" to go into an infinite loop
displaying NDFC memory addresses.

Signed-off-by: Valentine Barshak <vbarshak@ru.mvista.com>
Acked-by: Stefan Roese <sr@denx.de>
Acked-by: Sean MacLennan <smaclennan@pikatech.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>